Roof bolt anchor with camming element

ABSTRACT

A bolt anchor is comprised of a camming element and sleeve. The camming element is generally cylindrical, but with a larger midsection and reduced diameters at each end. The camming element includes a threaded bore along its axis and at least one stop near one end. The sleeve has a round collar with leaves extending from the collar parallel to the axis of the collar and each other. The stop maintains the assembly of the camming element and sleeve. Prongs on the sleeve prevent the retraction or turning of the bolt anchor when a bolt is installed in a hole. Reduced material thickness associated with the leaves produces hinges which allow the leaves to be more easily deformed outwardly. Inserting a bolt and anchor assembly into the hole and turning the bolt pulls the camming element into the sleeve and creates a wedging effect in the hole.

RELATED U.S. APPLICATION DATA

This application is a Continuation-in-Part of U.S. patent applicationSer. No. 13/112,196, filed on May 20, 2011 now U.S. Pat. No. 8,215,875.It therefore claims priority from U.S. patent application Ser. No.12/538,035, which in turn claims priority from U.S. Pat. No. 7,959,379B2, filed on Aug. 7, 2009, which in turn claims priority from U.S.Provisional Application 61/156,669, filed on Mar. 2, 2009. The entiredisclosures contained in U.S. patent application Ser. No. 13/112,196,U.S. Pat. No. 7,959,379 B2, and U.S. Provisional Application 61/156,669,including the attachments thereto, are incorporated herein by reference.

BACKGROUND

Certain embodiments of the invention pertain to a bolt anchor. Thisapplication includes embodiments and claims pertaining to a bolt anchorhaving two communicating portions, the first portion communicatingwithin the second portion, and in response, the second portion outwardlydeforms to secure the bolt anchor within a hole or bore.

One of the primary uses for bolt anchors is to secure the roof of amine. Mine shafts sometimes experience cave-ins, collapses, or fallingrock due to the layered and stratified makeup of the earth. A mine shaftitself may cause fractures and weaknesses in the strata in its ceiling,or it may just expose an inherently weak and unstable layer. To assistin preserving the integrity of the ceiling, it is common to support theceiling with bolts anchored within rock layers above the ceiling. Platesbetween the bolt heads on the exposed ends of the bolts and the ceilingsare used to transfer force from the anchored bolts to the exposed layerof the ceiling. In some applications, the exposed end of the anchoredbolt is threaded. Onto these bolts, a nut is threaded, and the nut isused to place a preload on the bolt to set an initial lifting force tothe plates.

Holes, which are slightly oversized to the bolts, are drilled into theceiling. Sometimes the holes must be several feet deep to be sure ofanchoring the bolts in a stable layer of rock. Once the holes aredrilled, the bolts are inserted into the holes and anchored. There arethree methods for anchoring the bolts in the holes, mechanical,adhesive, and mechanically assisted adhesive. This application relatesto the mechanical aspect of the mechanically assisted adhesive method ofanchoring bolts, so the adhesive method will be discussed beforediscussing the relevant mechanical art.

Once the hole is drilled, a multi-component adhesive is placed in theblind end of the hole. The components of the adhesive are kept inseparate frangible packages to keep them from mixing, for once they do,a reaction occurs, and the adhesive begins to set up. The components ofthe adhesive are usually a hardener and a catalyst. When the frangiblepackages have been placed in the hole, a bolt is inserted and turnedrapidly to rupture the packages and thoroughly mix the adhesivecomponents. The adhesive is typically of a fast setting variety and maybegin to set after three to five seconds of mixing. For many mechanicalanchoring methods, the mechanical anchoring elements on the bolt assistin mixing the adhesive, and the increased resistance to mixing of thesetting adhesive activates the mechanical anchoring system.

In mine roof applications, different methods are employed to ensureengagement of the mechanical elements of a bolt anchor. In bolt anchors,the mechanical elements frequently comprise a camming element surroundedby a wedging element. The threaded mine roof bolt draws the cammingelement into the wedging element to drive the wedging element laterallyinto the walls of the hole, and this produces a wedging effect betweenthe camming element, the wedging element, and the sides of the hole.However, the wedging element must be maintained in position at leastlong enough for the camming element to engage it. Frequently, stops areattached to, or mounted on, the mine roof bolts. This means the stopswill turn with the bolt, while the wedging element does not turn. Ifheat or adhesive causes the stop to seize on the wedging element, thewedging element may be twisted with the bolt degrading the effectivenessof the anchoring system. Means for maintaining the camming element andthe wedging element in assembly, or contact, without reliance on a stopfixed to the bolt is necessary to avoid twisting of the anchoringelements. Several other problems such as ease of use and manufacture,and effectiveness are addressed by the several embodiments presented inthis application.

DESCRIPTION OF THE RELEVANT ART

U.S. Pat. No. 4,194,858 by Evans, titled Mine roof bolt anchorinstallation, is for a mine roof bolt anchoring apparatus. A coil springhaving fixedly attached washer members at each end encircles a mine roofbolt and is retained between radially projecting ears on the bolt and anexpansion anchor threaded on the bolt. The washer member which engagesthe bolt ears is slotted to receive the ears so that rotation of thebolt is transmitted to the spring and the other washer member. Thewasher member at the other end has a pair of stepped shoulders on theface opposite the spring which engages the lower end of the anchorshell. The latter is also provided with a pair of stepped shoulderswhich cooperate with those on the washer member to transmit rotationfrom the bolt to the anchor in one direction and allow relative rotationin the other. In this manner, a resin grouting cartridge placed in thedrill hole ahead of the anchor may be broken and its contents mixed byrotation of the bolt and anchor as a common unit, and the anchorexpanded to tension the bolt as the resin sets by rotation in theopposite direction.

U.S. Pat. No. 4,299,515 by Yates, et al., titled Rock reinforcementsystem, is for a mine roof bolt anchoring apparatus. A system forreinforcing a rock formation, such as in mining or tunneling operations,wherein an elongated bolt is anchored in a blind drill hole in the rockformation by both a mechanical expansion anchor and a resin groutingmix. The invention is particularly directed to novel means which preventrelative rotation of the bolt and anchor in one direction and allowrelative rotation in the opposite direction, whereby a conventional,two-compartment resin cartridge can be broken and its contents mixedwhile rotating the bolt and anchor in the first direction, and theanchor expanded to tension the bolt by reversing the direction ofrotation before the resin mix hardens. The novel means comprise a collarelement which is affixed to the end of the bolt above the expansionanchor and cooperatively engages a stop means on the anchor in only onedirection of bolt rotation. A number of alternative means are disclosedfor affixing the collar to the bolt.

U.S. Pat. No. 5,441,372 by Wilkinson, titled Rock bolt shell and cone,is directed to a shell for a rock bolt with a cone threadedly engagedthereto. An expandable shell has a cylindrical outer surface and raisedridges in relief on the exterior of the shell. One or more ridges arelocated along a curve non-congruent with a circumferential circle of thecylinder. In a disclosed embodiment, each ridge lies along a helix ofthe cylinder and ridges are paired such that the helix of a firstextends in one rotational direction while the curve of a second of thepair extends in the other rotational direction. Each helix forms anangle of forty-five degrees with a center line of the cylinder. Ridgesintersect such that “V”-shaped projections extend along the outside ofthe shell. The vertices of certain of the projections project a radiallymaximum amount while each of the legs of the “V” taper radially inwardlytoward the cylindrical surface as the leg extends away from the vertex.The cone, threaded for installation on a bolt rod has one or more axialindentations to improve grout flow about an installed bolt.

U.S. Pat. No. 4,592,687 by Piersall, titled Roof Bolt, discloses anexpansion bolt that has an elongated stud with a proximal and a distalend. The stud has a coaxially mounted sleeve and a nut at the distalend. An annular backing plate is carried on the stud between the sleeveand the nut. The backing plate essentially comprises of two annulardisks with the same inner radii, but different outer radii. The disksare joined together along their planar surfaces so that the same-sizedannuli form a common bore. The first, smaller disk faces the proximalend of the stud, toward the sleeve, and the second, larger disk, facesthe distal end of the stud, toward the nut. When a pre-determined torqueis applied, this nut is advanced axially toward the stud, bringing thenut into engagement with the backing plate. The nut acts as a stop. Insome embodiments, this backing plate may be welded in place on the stud,and a nut is not needed. The backing plate restrains the sleeve fromaxial movement along the stud, while allowing free rotational movementof the stud relative to the sleeve.

SUMMARY

In one embodiment, a bolt anchor comprises a camming element comprisingan axial bore and threads disposed therein, the camming elementterminating at opposing ends. The camming element has a midsectionbetween the ends that has a larger diameter than both ends. The cammingelement tapers down from the midsection to at least one of the smallerends.

In another embodiment, a bolt anchor comprises a camming elementcomprising an axial bore and threads disposed therein, the cammingelement terminating at opposing ends and having a midsection between theends that has a larger diameter than both ends. The camming elementtapers down from the midsection to at least one of the smaller ends. Thecamming element may further include a stop depending from one end. Thebolt anchor further includes a deformable sleeve receiving the cammingelement, the sleeve comprising a plurality of cleats formed on thecircumference of the sleeve.

In another embodiment, a bolt anchor comprises a camming elementcomprising an axial bore and threads disposed therein, the cammingelement terminating at opposing ends and having a midsection between theends that has a larger diameter than both ends. The camming elementtapers down from the midsection to at least one of the smaller ends. Astop depends from one end. A deformable sleeve is provided and mayreceive the camming element, wherein the sleeve comprises a collar and aplurality of leaves depending from the collar, an axial void defined bythe leaves and the collar, and a plurality of cleats formed on thecircumference of the sleeve.

In another embodiment, a mining roof bolt system is described, thesystem comprising a bolt that comprises external threads, and a cammingelement comprising an axial bore and threads disposed therein, thecamming element terminating at opposing ends. The camming element has amidsection between the ends that has a larger diameter than both ends.The camming element tapers down from the midsection to at least one ofthe smaller ends. A stop depends from one end. A deformable sleeve isprovided, the sleeve receiving the camming element, the sleevecomprising a plurality of cleats formed on the circumference of thesleeve.

In another embodiment, a mining roof bolt system is described, thesystem comprising a bolt comprising external threads. A camming elementcomprising an axial bore and threads disposed therein is provided, thecamming element terminating at opposing ends. The camming element has amidsection between the ends that has a larger diameter than both ends.The camming element tapers down from the midsection to at least one ofthe smaller ends. A stop depends from one end. A deformable sleevereceiving the camming element is provided, the sleeve comprising acollar and a plurality of leaves depending from the collar, an axialvoid defined by the collar and the leaves, and a plurality of cleatsformed on the circumference of the sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a bolt anchor comprising a camming elementwith a tapered body and a sleeve, the sleeve depicted in phantom.

FIG. 2 is a front or side view of a tapered camming element.

FIG. 3 is a front or side view of a sleeve which may be used to couplewith a camming element in a bolt anchor arrangement.

FIG. 4 is a front or side view of a bolt anchor with a tapered cammingelement and sleeve couple to bolt “B”.

FIG. 5 is a front or side view of another variation of a bolt anchorwith a tapered camming element coupled to bolt “B”.

FIG. 6 is top view of the camming element of FIG. 1 depicting therecesses 38 and axial bore 28.

FIG. 7 is a bottom view of the sleeve depicting the prongs 50 and theaxis void 46 formed therethrough.

FIG. 8 is a top or bottom view of a clip ring 32 a.

FIG. 9 shows the assembly of an embodiment of a camming element and anembodiment of a sleeve assembled to form a bolt anchor.

FIG. 10 is a front view of another variation of a tapered cammingelement for use in a bolt anchor.

FIG. 11 is a side view of the camming element of FIG. 10.

FIG. 12 is a front or side view of another embodiment of a sleeve of thebolt anchor.

FIG. 13 shows the assembled camming element and sleeve of FIG. 9 with abolt threaded into the body.

FIG. 14 is an assembly of a bolt anchor according to a first embodimentof the present invention, showing a camming element tapered on both theproximal and distal ends assembled with a sleeve on a roof bolt.

FIG. 15 is a side view of an embodiment of the novel camming elementaccording to the present invention.

FIG. 16 is a perspective view of the novel camming element of FIG. 15.

DESCRIPTION OF THE EMBODIMENTS A) Discussion of Parent ApplicationEmbodiments

Referring now to FIG. 1 through FIG. 4 and FIG. 6 through FIG. 8, thesedrawings show a bolt anchor arrangement claimed in an earlier patentapplication in the priority chain with respect to the present invention,generally denoted by the reference character 10. The bolt anchor 10 isutilized for securely anchoring a bolt “B” within a hole of a roof,wall, floor or other similar surface into which a bolt “B” may beinserted. The bolt anchor 10 comprises a camming element 20 and adeformable sleeve 40. The camming element 20 comprises a generallytapered surface. The sleeve 40 engages the camming element 20, whereinthe sleeve 40 communicates along the exterior surface of the cammingelement 20. In response to relative downward movement of the cammingelement 20 along bolt “B”, the sleeve 40 engages the increasingly widersurface of the camming element 20, outwardly deforming the sleeve 40 andsecuring the anchor 10 and bolt “B” into position within the hole of theroof, wall, floor or other surface.

The camming element 20 comprises a shaft 22 terminating at an end 24 andan end 26, the ends 24 and 26 disposed opposite thereof. The ends 24 and26 having different diameters and the diameter of the shaft 22therebetween the ends 24 and 26 may be tapered. The camming element 20may further comprise an axial bore 28 having a plurality of internalthreads 30. The bore 28 and threads 30 permit coupling of the cammingelement 20 with a bolt “B” having external threads thereon. The cammingelement 20 may also include a stop 32 depending from one of the ends 24or 26.

The shaft 22 may be described as having two segments, including atapered first segment 22 a and a linearly elongated second segment 22 b.The first segment 22 a may be generally described as having a conicalform. End 24 forms one margin of the conical form. The segments 22 a and22 b interface at a junction 22 c. The diameter of the junction 22 c isgenerally similar or the same as the diameter of end 26, the end 26forming one margin of the second segment 22 b. Thus, the conical form ofthe first segment 22 a may be described as having a diameter at end 24greater than the diameter of either the junction 22 c or the end 26terminating the second segment 22 b. Tapered first segment 22 a of body20 provides a camming element in bolt anchor 10.

The second segment 22 b may function as a guide for the sleeve 40. Thelinearly elongated form of the second segment 22 b has a diametersmaller than that of the void 46 formed in sleeve 40. Thus, the secondsegment 22 b may guide the sleeve 40 (via void 46) into communicationand/or engagement with the first segment 22 a and its conical form.

The stop 32 depends from one of the ends 24 or 26. In but one example,depicted in FIG. 2 and FIG. 4, the stop 32 depends from end 26. In onevariation, the stop 32 is an integral element formed during thefabrication of the body 20. In another variation, the stop 32 isremovable from and attachable to the camming element 20. In such avariation, the stop 32 may comprise a returnably resilient clip ring 32a that may be inserted into a groove or channel 34 formed along theexterior surface and along the outer circumference at or near the end 26of the camming element 20. It is also envisioned that the stop 32 maycomprise a pliable or flexible grommet or other similar device that maybe positioned to depend from the end 26 or positioned within a groove orchannel 34 provided for dependence from the end 26. The stop 32 mayengage one or more prongs or teeth 50 disposed on and/or depending fromthe sleeve 40.

Camming element 20 may further include one or more recesses 38 formed inthe exterior surface of the body 20. Each recess 38 may be disposed witha terminal end 38 a of the recess 38 co-extensive with a terminal end 24or 26 of the body 20, and an opposing end 38 b co-planar with thecamming element 20. In this variation, the recess 38 may have a variabledepth along its length, wherein the depth is greatest at or near theco-extensive end 38 a and gradually decreasing to substantially no depthat or near the co-planar end 38 b. Each recess 38 accommodates adhesiveresins or other similar chemicals that may be used to further secure abolt “B” within a hole. As bolt “B” is mechanically rotated within thebody 22, the bolt “B” and anchor 10 mix the resin, with the resin pushedthrough the recess(es) 38 from the end 38 b toward the end 38 a.

In another variation, the camming element 20 may further include one ormore fins 36 depending from the exterior surface of camming element 20.Each fin 36 may be disposed along the exterior surface of the cammingelement 20 to inhibit excessive rotation of the sleeve 40 as the cammingelement 20 and sleeve 40 engage during operation. Each fin 36 may bedefined by a height that is greater than the internal circumference ofthe sleeve 40. Each fin 36 engages the space or channel 52 formedbetween two leaves 44 of the sleeve 40, as described in greater detailbelow.

In one variation, the sleeve 40 comprises a collar 42 and a plurality ofleaves 44 depending from the collar 42. The collar 42 and leaves 44define an axial void 46 within the sleeve 40, the void 46 accommodatingor receiving a segment of camming element 20. The space or channel 52between leaves 44 terminates at a joint generally defined by asemi-circular cut-out 54 utilized to reduce the stress placed on theleaves 44. A plurality of cleats 48 may be disposed or formed on theouter circumference of the sleeve 40, such as along all or some portionof the vertical length of one or more of the leaves 44. The sleeve 40may further include one or more prongs or teeth 50 depending from thecircumference of the collar 42 adjacent the free terminal end of thecollar 42. The prongs or teeth 50 engage the stop 32, thereby inhibitingthe sleeve 40 from moving beyond a certain threshold relative to thecamming element 20 should the leaves 44 prematurely release the cammingelement 20.

The collar 42 forms one portion of the sleeve 40. The collar 42 providesa structural support for the leaves 44 depending therefrom. As theleaves 44 outwardly deform under pressure from the camming element 20,the collar 42 operates to strengthen the leaves 44 and to inhibitpremature failure at the junction of the collar 42 and leaves 44. Thecollar 42 further provides structural support for one or more prongs orteeth 50 that may depend from the sleeve 40.

Each one of the leaves 44 may be upwardly depending from the collar 42.A leaf comprises an interior surface having a radius that iscomplementary to the general radius and form of the camming element 20.The leaf 44 also comprises an exterior surface having a radius that issimilar to the interior surface and inner radius. A plurality of cleats48 may be formed on and/or depending from the exterior surface of theleaf 44. In one variation, each cleat 48 may be formed and/or disposedin a similar manner, providing uniformity to the gripping surface thatthe leaf 44 and cleat(s) 48 provide. For example, as depicted in FIG. 3,the cleats 48 are serially arranged having a surface 48 a, a surface 48b and a surface intermediately disposed between surfaces 48 a and 48 b.Surfaces 48 a and 48 b may be substantially similar in configuration,sharing similar dimensions (e.g. length, width, surface area and anglefrom the leaf 44). Surface 48 c interconnects the surfaces 48 a and 48b, generally deflected at or approximately at a right (90°) angle to thesurfaces 48 a and 48 b, respectively. This arrangement is repeated alongthe surface of the leaf 44. The outermost surface of the arrangement,generally denoted by the reference character 48 d, provides a generallypointed surface that may be used to embed the leaves 44 into surroundingmaterial, including wood, metal, plastic, soil, rock, chemical adhesiveor a combination thereof, among several possibilities and combinations.In such an embodiment, as the leaves 44 of sleeve 40 outwardly deform,the surface 48 d of one cleat 48 may embed, impinge or otherwise engagewith the surrounding material to provide rigid anchoring of the anchor10.

FIG. 5 depicts another variation in the parent application, wherein thestop 32 is a fixed or permanent structure on the bolt “B” body. In thisvariation, the axial length of the collar 42 (of sleeve 40) islengthened. As the bolt “B” is mechanically rotated, the stop 32 movesrelatively upward toward the end of the collar 42, and then engages thecollar 42 and urges the collar 42 upward. In so urging, the leaves 44are outwardly deformed as each engages the progressively wider diameterof the camming element 20. The cleats 48 of the leaves 44 engage thesidewall of the hole and secure the bolt anchor 10 and bolt “B” in placewithin the hole.

FIG. 9 shows a variation of a bolt anchor 110 comprised of the assemblyof a camming element 120 and sleeve 140. Camming element 120 inserts,distal end 126 first, into the axial void defined by leaves 144extending from collar 142 of sleeve 140. Stops 132 on camming element120 engage with retention tabs 156 on the extended ends of leaves 144 tomaintain assembly of camming element 120 and sleeve 140.

In FIG. 10, stops 132 may be seen on camming element 120 at, or near,distal end 126. FIG. 11 shows stops 132 extending radially from cammingelement 120. In the variation shown in FIG. 11, stops 132 themselveshave a tapered shape with insertion face 133 of stop 132 merging withthe surface of camming element 120 at the lower edge of insertion face133 and expanding up and away from the surface of camming element 120 tothe upper edge of insertion face 133 which extends out from cammingelement 120. From the upper edge of insertion face 133 to the surface ofcamming element 120 is located locking face 135. The tapered shape ofstop 132 assists in the assembly camming element 120 and sleeve 140 ofbolt anchor 110. While stops 132 are tapered as just described, this isnot necessary for all embodiments of camming element 120. Otherembodiments may have stops extending from camming element 120 withessentially prismatic shapes.

Camming Element 120 has an axial bore 128 extending from proximal end124 to distal end 126. Axial bore 128 is indicated by dotted lines inFIGS. 9, 10, 11, and 13. Axial bore 128 has internal threads, whichmatch the external threads of a respective mine roof bolt.

FIG. 12 separately shows another variation of a sleeve 140 of boltanchor 110. In its larger aspects, sleeve 140 is comprised of collar 142with leaves 144 extending from collar 142 generally parallel to the axisof collar 142 and generally parallel to each other. Leaves 144 arelocated around the circumference of collar 142 with spaces or channels152 between adjacent leaves 144.

Leaves 144 may have cleats 148 on their exterior surfaces to moresecurely engage the sides of a hole into which a bolt and bolt anchor110 are inserted. Cleats 148 may have several shapes, or embodiments.The variation of cleats 148 shown FIG. 12 is substantially similar tothe embodiment of cleats 48 shown in FIG. 3 and discussed with respectto FIG. 3. As such, the outermost surface of the arrangement provides agenerally pointed surface that may be used to embed leaves 144 intosurrounding material, including wood, metal, plastic, soil, rock,chemical adhesive or a combination thereof, among several possibilitiesand combinations. In such a variation, as leaves 144 of sleeve 140outwardly deform, the outermost, pointed, surface a given cleat 148 mayembed, impinge or otherwise engage with the surrounding material tosecure anchoring of the anchor 110. The variation of cleats 48 and 148shown in FIGS. 3 and 12 and discussed with respect to those figures areby way of example and the illustration and description of thoseembodiments of cleats should not be considered as requiring thosespecific embodiments of cleats.

FIG. 13 shows a bolt 170 inserted through sleeve 140 and threaded intocamming element 120 of an assembled bolt anchor 110. When the boltanchor 110 end of the assembly of bolt 170 and bolt anchor 110 isinserted into a hole, resiliently deformable prongs 150 flex andresiliently deform to allow the insertion of the bolt 170 and boltanchor 110 assembly into the hole. Resilient prongs 150 engage the sidesof the hole and resist the retraction of the bolt 170 and bolt anchorassembly 110 and the turning of sleeve 140 and therefore the turning ofbolt anchor assembly 110.

B) Discussion of Current Embodiments

FIG. 14 shows an embodiment of a mine roof bolt incorporating thecurrent invention. A bolt anchor 210 is depicted, and may be utilized ina variety of applications. By way of example only, one such applicationincludes the use of an anchor 210 in an underground mineral miningenvironment, such as an underground coal mine. In this example, ananchor 210 comprises a camming element 220 and is threadably coupled toa threaded bolt “B” that forms part of the roof-bolt system (roof-boltand roof-plate) commonly employed in underground mining to providestructural integrity to the roof-top above the working miners.

In order to perform appropriately, it is important that the bolt anchor210 effectively pierce the frangible containers of adhesive and mix themthoroughly without bunching or jamming. The mixed liquid solution mustbe enabled to move downward past camming element 220 to make contactwith the sleeve 240 and roof bolt 270. In order to achieve the purposesof the invention, camming element 220 is constructed in this embodimentto be a single element comprised of a proximal end 224, a distal end226, and a midsection region 225. Camming element 220 is further definedsuch that the outer diameter of midsection 225 is greater than the outerdiameter of proximal end 224 and distal end 226. As further shown bydotted lines in FIG. 14, camming element 220 further includes an axialbore 228 which is located in the center and is threaded. The threads inaxial bore 228 are constructed such as to conform with and communicatewith the threaded end of roof bolt 270. The smaller size of proximal end224 allows camming element 220 to effectively pierce the frangiblecontainers of adhesive.

FIG. 15 shows a side view of an embodiment of camming element 220 thatmore fully reveals some of its features. In addition, FIG. 16 is aperspective view of the same embodiment of camming element 220 that isshown in FIG. 15. In the embodiment of camming element 220 shown in FIG.15 and FIG. 16, midsection region 225 is closer to proximal end 224 thanto distal end 226. However, other arrangements are certainly possible inkeeping with the intent and spirit of the invention. As further shown inFIG. 15 and FIG. 16, camming element 220 is further defined by one ormore ports 227. In one embodiment, as shown in FIGS. 15 and 16, the portis achieved by reducing the diameter in a portion of camming element220, which has the effect of flattening the camming element 220 in theport 227 area, creating a gap between camming element 220 and the sideof the hole. The port(s) 227 serve the purpose of enabling the mixedadhesive to more effectively flow down past camming element 220. In thisembodiment, one or more port(s) 227 are achieved by reducing thediameter in a portion of the outer diameter of camming element 220;however, other means for achieving a port for the effective flow ofmixed adhesive may be utilized in keeping with the scope and purposes ofthis invention.

In another embodiment, camming element 220 may be further characterizedby the inclusion of one or more stop(s) 232 located at the end of distalend 226 of camming element 220. As shown in FIG. 15 and FIG. 16, stop232 is constructed such at to include a bottom insertion face 233 and atop locking face 235.

The camming element 220 is engaged by a deformable sleeve 240. Thesleeve 240 comprises a collar 242 and a plurality of upwardly dependingleaves 244, wherein each leaf 244 comprises a plurality of cleats 248.In operation, the one or more stop 232 will engage with a properly sizedaperture between cleats 248 at the proximal portion of sleeve 240.

To install the bolt anchor 210 as coupled to the bolt 270, a hole isdrilled into the roof top material, wherein the hole has a diameterlarger than the bolt anchor 210 and bolt 270. The bolt 270 is insertedthrough an aperture in the roof-plate. The anchor 210 is threadablycoupled to the bolt 270. The bolt 270 and anchor 210 are inserted intothe hole in the roof-top. The bolt 270 is mechanically rotated, causingthe resin or chemical adhesive material to mix and spread through thehole, quickly creating a bonding quality within the hole and between thebolt 270, adhesive and hole. The terminal end of the bolt 270 engagesthe roof top, but does not substantially penetrate into the roof topmaterial beyond the end of the hole. Against this resistance, the bolt270 continues to rotate causing the threaded camming element 220 to moverelatively downward along the bolt 270. Concurrently, the sleeve 240engages the sides of the hole via the prongs or teeth 250 depending froman end of the sleeve 240. The prongs 250 provide resistance and hold thesleeve 240 in a relatively fixed position, allowing the camming element220 to engage the leaves 244 of the sleeve 240. As the camming element220 engages the leaves 244, by entering the void defined by the collar242 and leaves 244, and in response to the wider diameter surfaceprovided near the top end of each leaf 244, each leaf 44 is outwardlydeformed toward the sides of the hole. The cleats 248 on each leaf 244engage the sides of the hole and provide a fixed position of the anchor210.

To anchor the bolt 270 and bolt anchor 210 assembly, bolt 270 is turnedin the rotational direction that causes the camming element 220 totranslate along the threaded portion of bolt 270 toward sleeve 240. Thehead, or head and washer, on bolt 270 prevents bolt 270 from beingpulled into the hole during the anchoring process. Prongs 250 on sleeve240 prevent the rotation of sleeve 240 and camming element 220, ensuringrelative rotation between bolt 270 and camming element 220 and ensuringtranslation of camming element 220 along the threaded portion of bolt270. As camming element 220 moves into sleeve 240, prongs 250 alsoprevent the linear movement of sleeve 240, causing camming element 220to move linearly with respect to sleeve 240 and move more deeply intothe axial void defined by leaves 244 of sleeve 240. As camming element220 moves into this axial void, the tapered shape of the distal end ofcamming element 220 drives leaves 244 outward into engagement with thesides of the hole into which bolt 270 and bolt anchor 210 are located.This creates a wedging effect between camming element 220, leaves 244,and the sides of the hole. Tension in the bolt shaft of bolt 270 betweenthe bolt head and camming element 220 maintain camming element 220engaged in leaves 244 and bolt anchor 210 in the hole. When a selectedtorque resistance is measured in the turning of bolt 270, the installerof bolt 270 and bolt anchor 210 deems that the desired tension in bolt270 has been reached and the installer ceases to turn bolt 270.

In another embodiment, each cleat 248 may be formed and/or disposed indifferent ways. For example, a plurality of tines or spines may beprovided in place of the surfaces 248 described above. The tines orspines may outwardly project so as to provide a way to embed, impinge,pierce or burrow into the surrounding material.

If provided, each one of the prongs or teeth 250 may outwardly projectfrom the surface of the collar 242 at an angle incident to the surfaceof the collar 242. The prongs or teeth 250 extend the relativecircumference or diameter of the sleeve 240 (and collar 242) and providea way by which the camming element 220 may engage and inhibit the sleeve240 from completely disengaging from the camming element 220 duringinstallation or operation.

Another feature that sleeve 240 may have are hinges 258 located in thearea where leaves 244 join collar 242. Hinges 258 are created by areduction of thickness in the material of sleeve 240 at that location.Hinges 258 reduce the amount of force required to bend leaves 244 fromthe initial position of leaves 244. This reduces the amount of forceneeded to pull camming element 220 into further engagement with sleeve240 and leaves 244 and thus reduces the amount of rotational forceneeded to be applied to a bolt employing bolt anchor 210. Reducing therotation force needed to anchor bolt anchor 210 reduces the amount ofrotation force or linear force that prongs 150 must resist to preventrotation of bolt anchor 210.

It is to be understood that the embodiments and claims are not limitedin application to the details of construction and arrangement of thecomponents set forth in the description and illustrated in the drawings.Rather, the description and the drawings provide examples of theembodiments envisioned, but the claims are not limited to any particularembodiment or a preferred embodiment disclosed and/or identified in thespecification. The drawing figures are for illustrative purposes only,and merely provide practical examples of the invention disclosed herein.Therefore, the drawing figures should not be viewed as restricting thescope of the claims to what is depicted.

The embodiments and claims disclosed herein are further capable of otherembodiments and of being practiced and carried out in various ways,including various combinations and sub-combinations of the featuresdescribed above but that may not have been explicitly disclosed inspecific combinations and sub-combinations. Accordingly, those skilledin the art will appreciate that the conception upon which theembodiments and claims are based may be readily utilized as a basis forthe design of other structures, methods, and systems. In addition, it isto be understood that the phraseology and terminology employed hereinare for the purposes of description and should not be regarded aslimiting the claims.

Furthermore, the Abstract is neither intended to define the claims ofthe application, nor is it intended to be limiting to the scope of theclaims in any way. It is intended that the application is defined by theclaimed appended hereto.

1. A bolt anchor comprising: a camming element comprising opposing endsand a midsection between said ends; said opposing ends being a proximalend and a distal end; the outer diameter of said midsection beinggreater than the outer diameters of said opposing ends, the cammingelement generally tapering from said midsection toward said ends andhaving at least one port on the exterior surface of said midsection;said camming element further comprising an axial bore and threadsdisposed therein; at least one stop depending from said camming elementnear said distal end; a deformable sleeve receiving and engaging saiddistal end of said camming element, said sleeve comprising a pluralityof leaves parallel to the axis of said sleeve, said sleeve having aninner circumference and an outer circumference; wherein said at leastone stop maintains said camming element and said sleeve in engagement.2. The bolt anchor of claim 1, wherein: said at least one stop comprisesat least one radial projection from said camming element, said at leastone radial projection extending from said camming element to a heightgreater than the inner circumference of said sleeve but no greater thanthe outer surface of said midsection of said camming element.
 3. Thebolt anchor of claim 2, wherein: at least two adjacent said leaves ofsaid sleeve have a gap between them sufficient to accommodate said atleast one stop, said sleeve having at least one said gap per each saidstop.
 4. The bolt anchor of claim 3, wherein: said sleeve furthercomprises at least one retention tab at least partially spanning eachsaid gap receiving a said stop, said at least one retention tabmaintaining the receipt of said camming element in said sleeve.
 5. Thebolt anchor of claim 1, further comprising: at least one prong extendingradially outward from the outer circumference of said sleeve, said atleast one prong extending radially to a distance greater than the radiusof a hole for which said bolt anchor is intended and said at least oneprong being generally directed away from said proximal end of saidcamming element to allow the insertion of said bolt anchor into saidhole but resist the extraction of said bolt anchor from said hole. 6.The bolt anchor of claim 5, wherein: said at least one prong is locatednear the end of said sleeve opposite to the end of said sleeve intowhich said camming element is received.
 7. The bolt anchor of claim 1,further comprising: cleats on the outer circumference of said sleeve. 8.The bolt anchor of claim 1, further comprising: a region of reducedmaterial thickness at the end of said leaves opposite to the end of saidsleeve into which said camming element is received.
 9. A mining roofbolt system comprising: a bolt comprising external threads; a cammingelement comprising: opposing ends and a midsection between said ends;said opposing ends being a proximal end and a distal end; the outerdiameter of said midsection being greater than the outer diameters ofsaid opposing ends, the camming element generally tapering from saidmidsection toward said ends and having at least one port on the exteriorsurface of said midsection; said camming element further comprising anaxial bore and threads disposed therein; at least one stop dependingfrom said camming element near said distal end; a deformable sleevereceiving and engaging said distal end of said camming element, saidsleeve comprising a plurality of leaves parallel to the axis of saidsleeve, said sleeve having an inner circumference and an outercircumference; wherein said at least one stop maintains said cammingelement and said sleeve in engagement.
 10. The mining roof bolt systemof claim 9, wherein: said at least one stop comprises at least oneradial projection from said camming element, said at least one radialprojection extending from said camming element to a height greater thanthe inner circumference of said sleeve but no greater than the outersurface of said midsection of said camming element.
 11. The mining roofbolt system of claim 10, wherein: at least two adjacent said leaves ofsaid sleeve have a gap between them sufficient to accommodate said atleast one stop, said sleeve having at least one said gap per each saidstop.
 12. The mining roof bolt system of claim 11, wherein: said sleevefurther comprises at least one retention tab at least partially spanningeach said gap receiving a said stop, said at least one retention tabmaintaining the receipt of said camming element in said sleeve.
 13. Themining roof bolt system of claim 9, further comprising: at least oneprong extending radially outward from the outer circumference of saidsleeve, said at least one prong extending radially to a distance greaterthan the radius of a hole for which said bolt anchor is intended andsaid at least one prong being generally directed away from said proximalend of said camming element to allow the insertion of said bolt anchorinto said hole but resist the extraction of said bolt anchor from saidhole.
 14. The mining roof bolt system of claim 13, wherein: said atleast one prong is located near the end of said sleeve opposite to theend of said sleeve into which said camming element is received.
 15. Themining roof bolt system of claim 9, further comprising: cleats on theouter circumference of said sleeve.
 16. The mining roof bolt system ofclaim 9, further comprising: a region of reduced material thickness atthe end of said leaves opposite to the end of said sleeve into whichsaid camming element is received.
 17. A bolt anchor comprising: acamming element comprising: opposing ends and a midsection between saidends; said opposing ends being a proximal end and a distal end; theouter diameter of said midsection being greater than the outer diametersof said opposing ends, the camming element generally tapering from saidmidsection toward said ends and having at least one port on the exteriorsurface of said midsection; said camming element further comprising anaxial bore and threads disposed therein; at least one stop dependingfrom said camming element near said distal end; a plurality of parallellongitudinal leaves defining a void about an axis, each said leaf beingattached to any adjacent leaf on at least one end, said leaves beingdeformable out from said axis, and said plurality of leaves receiving inone end of said void said distal end of said camming element; whereinsaid at least one stop maintains said distal end of said camming elementin said void.
 18. A bolt anchor comprising: a camming elementcomprising: opposing ends and a midsection between said ends; saidopposing ends being a proximal end and a distal end; the outer diameterof said midsection being greater than the outer diameters of saidopposing ends, the camming element generally tapering from saidmidsection toward said ends and having at least one port on the exteriorsurface of said midsection; said camming element further comprising anaxial bore and threads disposed therein; at least one stop dependingfrom said camming element near said distal end; a plurality of parallellongitudinal leaves defining a void about an axis, said leaves beingmaintained around said void about said axis by a collar, said leavesbeing deformable out from said axis, and said plurality of leavesreceiving in one end of said void said distal end of said cammingelement; wherein said at least one stop maintains distal end of saidcamming element in said void.
 19. A camming element for a mine roof boltanchor employing a camming element and expansion sleeve, said cammingelement comprising: opposing ends and a midsection between said ends;said opposing ends being a proximal end and a distal end; the outerdiameter of said midsection being greater than the outer diameters ofsaid opposing ends, the camming element generally tapering from saidmidsection toward said ends and having at least one port on the exteriorsurface of said midsection; said camming element further comprising anaxial bore and threads disposed therein and sized to fit a respectivemine roof bolt.